Contractions?

I'm full term and I was 50 effaced and 1 cm dilated so I wanted to move things along. I started having sex with my husband again and eating pineapple and walking every night. Tonight after sex and eating half a pineapple I started having pains. I can barely sit down because I get pains down there. And I get pains every 3 to 4 minutes that it's like pressure in my whole belly and pain in my lower back and pain in down there. But at times it hurts so so bad. Contractions or just my body.